JPS604785B2 - disc printing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a rotating support having type letters in relief, the letters being brought to a position opposite the printing surface, and in the printing position the letters are hammered to print on the printing surface. Concerning improvements to disc printing machines that perform

In known printing machines of this type, the type characters are supported by sacrificial radial arms of a rotating support in the form of a disc or cone.

These arms are occupied at regular angular intervals so that the typed characters are evenly spaced around the circumference. As a result, the type character to be printed is selected by a constant number of angular steps. Since the rotating support is usually made of molded synthetic plastic,
It is difficult to obtain extremely accurate angular positions of each type character. This is because mechanical internal stresses distort the support when it is removed from the mold. Moreover, if the angular step between typed characters is to be constant, the size of this step is determined by the widest character, which makes the rotating support unduly large and therefore heavy.

In order to obtain higher printing speeds, it is sought to reduce the diameter and inertia of the support by alternating wide and narrow characters. This produces a special order in which the type characters appear on the support, and none of this order corresponds to the code order of the American Standard Code of Information Interchange (ASCO), which is widely used for information exchange. This lack of correspondence complicates the electrical circuitry that controls the rotation of the support. It is an object of the present invention to provide an improvement to a disc printing press that eliminates the above-mentioned defects.

According to the invention, this object is achieved by the following arrangement.

That is, the type characters are held irregularly spaced about the axis of rotation of the support such that the arc occupied by each type character varies within the type character, and an indicating device is provided on the support to indicate the angular position of each type character. characterized in that it comprises a reading device which reads the pointing device and from which it emits a signal controlling the printing of each character in order to obtain a uniform distribution of printed characters on the printed copy. FIG. 1 shows a rotating support 1 consisting of a synthetic plastic disk consisting of steerable radial arms 2, each of which is provided at its free end with a type letter 3 in relief. .

Each arm also has a hole 4, the angular position of which is positioned very precisely around the axis of rotation of the disc 1 with respect to the angular position of the associated type character 3. As shown in FIG. 2, the disk 1 is mounted on the shaft of a servo motor 5, so that each type character 3 can be moved to a position opposite the cylinder 6 through which the paper 7 passes.

This paper constitutes the printing paper. The device for guiding the paper onto the cylinder 6 as well as the device for controlling the rotation of this cylinder are not shown. This is because these are well known per se and do not form an essential part of the present invention. In order to print desired characters, the motor 5 is rotated until the characters are positioned opposite the paper 7.

After the disk 1 has stopped, the electromagnetically driven hammer 8 is activated to press the characters 3 against the paper 7. Since the arm is mirrorable, the arm 2 can move freely. In order to ensure that the motor 5 stops at the correct position, the printing machine is equipped with a photoelectric system that determines the exact position of the characters to be printed. The device includes a light source 9 placed on one side of the disc 1. When the arm 2 is correctly positioned, the light beam from the light source passes through the hole 6 and hits the photodetector 10. On top of that,,
One of the arms 2 of the disc 1 has a hole 30 closer to the center of the disc.
, so that a second photodetector (not shown) can be used to determine the predetermined angular position of the disk, if necessary. The controller for the servo motor 5 is shown in FIG. 3, which also shows the light source 9 and the photoelectric detector 10.

Detector 1, every time arm 2 passes in front of the detector, hole 4
receives a beam of light passing through it. The light beam also impinges on the photoelectric detector each time the radial slit separating two consecutive arms 2 passes through it. As a result, the photoelectric detector emits an electrical pulse shaped by trigger 1. The pulse output of the trigger passes through a divider by two circuits 31 and then enters a counter 12 whose output is connected to a comparator 13 . This comparator 13 also receives an encoded signal from register 4, which indicates the character to be printed. When the number of pulses received from photodetector 10 before the last print corresponds to the encoded signal from register 4, comparator 13 responds to this coincidence by sending a signal on output line 15 to activate motor 5. make it stop. Comparator 13 is also responsive to the difference between the position given by the signal from register 14 and the position actually occupied by disk 1.

Therefore, the comparator outputs one or the other of output lines 16, 17.
A signal is given to rotate the motor 5 in one direction or the other to bring the desired typed character to the printing position. Devices with which it is possible to determine by means of a comparator whether the disk 1 is to be rotated in one direction or the other direction to reach the desired position more rapidly are well known and will therefore not be described in detail. The three output lines 15, 16, 17 of the comparator 13 are connected to the circuit 1
8 and this circuit controls motor 5. Output line 1
5 is not only applied to circuit 18, but also
The other input of the AND gate is also connected to the output of trigger 11. Thus, when the motor is stopped, while being pulsed by the trigger 11, the gate 20 emits an electrical signal which activates the hammer 8 via the monostable multipipulator 19 and the amplifier 21. As shown in FIG.
1 has an input 22 for controlling the amplification factor of the amplifier, which input is directly connected to the output of the photodetector 10.

This arrangement allows the force driving the hammer 8 to be varied as a function of the amplitude of the signal emitted by the photoelectric detector 10 as well. In this way it is possible to adapt the force with which the hammer strikes the arm 2 to the surface of the type character to be printed. It is clear that the force used to print the character "." must be less than the force used to print a "W". Therefore, the force striking the arm (printing characteristics) is controlled by information relating to the surface area of the characters to be printed. As shown in FIG. 4, this can be done by replacing the round hole 4 of FIG. 1 with a slit 24. The radial length of the slit is
Corresponds to the surface dimensions of type letters. FIG. 4 also shows that arm 2 is medium wide for a letter such as "M" than for a medium narrow letter such as "1". this is,
The diameter of the disk 1 is reduced to a minimum, thus making it possible to limit the inertia of the disk, thereby allowing very fast accelerations and decelerations and thus high printing speeds. The holes 4 and 24 may be simple openings, or may be gates coated with a light-permeable material, or may be light-permeable inserts provided in the arm 2.

If it is desired to print with varying spacing as a function of the length of each printed character (variable printing step: other printing characteristics), the present invention may e.g. It can be equipped with a device that

This instruction is provided by an optical system that detects the inside of the arm and emits an electrical signal that determines the size of the printing step (relative movement between the disk 1 and the printing surface) of the character to be printed. It can be obtained, for example, from within the arms containing the respective letters. According to the invention, this instruction also includes arm 2
By the use of holes, the printing force can also be obtained in the same way as controlling.

Several methods are used to ensure accurate positioning of type letters for printing, to vary the printing force depending on the area size of the type letters, and/or to print with varying spacing depending on the length of the type letters. There are possible implementations.

One such embodiment is shown in FIG. Referring to FIG. 5, the free end of each arm 2 is provided with at least one projecting stop piece 25 whose height varies depending on the desired printing force for type letters on the arm.

This stop piece 25 cooperates with a member 26 which moves towards and away from the center of the disc 1. This member comprises at least one V-shaped notch 27 which, when engaged by the stop piece 25, serves to fix the disc 1 in the desired printing position. The downward movement of member 26 required to secure the disc is a function of the height of stop piece 25, and the magnitude of this movement provides a signal that allows control of the printing force. Figure 5 1
In the embodiment shown, the size or position of the cutout 27, or the size or position of the stop piece 25, or any combination of the size and position of the cutout and/or the stop piece, can be adjusted to determine the printing characteristics of either or both. It can be used to give instructions.

FIG. 6 shows another embodiment for ensuring the correct printing position of the disc 1.

Each arm 2 has a ferromagnetic member 28, and the printing machine
8 is provided with a magnetic pickup (not shown) located beside the circular path along which it moves. According to the invention, it is only required that the disc 1 be equipped with a device that indicates the exact position at which the disc must stop in order to print a character.

It is also possible to provide a device for indicating the two above-mentioned printing characteristics, namely the desired printing power and/or printing step, which varies depending on the type of character to be printed.
The device for indicating the interior or surface area of each type character need not be incorporated into the disc 1; instead, the device
It will be clear to those skilled in the art that it may also consist of one or more independent elements, such as one or more cams which rotate together and together with the disc 1 form a rotating support.

Although the invention has been described herein with reference to preferred embodiments, those skilled in the art will recognize that changes may be made in form and detail of the invention without departing from its spirit and scope.

[Brief explanation of drawings]

FIG. 1 is a front view of a portion of the rotating support, FIG. 2 is a cutaway side view of the mechanical form of one embodiment, and FIG. 3 is a block diagram of an electric circuit that controls the rotation of the support. The figures 4 to 6 show three different embodiments of the arm supporting the typed characters. 1...Rotating support body, 2...Arm, 3
...Type letter, 8...Hammer, 4,2
4, 25, 28...Instruction device. Powerful techniques for the role of a demon. Evening friend J Takatasa. The next step is to finish the work.

Claims (1)

[Claims] 1 a type character support disk rotatable about an axis;
a type character support arm provided on the disc and extending radially around the disc and having a type character support portion having a type character in relief at an outer end, the type character being small to small; having widths and dimensions up to large, the angular spacing between the type character support portions being equal, the type character support portions being of varying widths, the width being proportional to the width of the type character; thereby reducing the dimensions and inertia of the disc to a minimum, and further comprising a hammer device for striking the individual characters of said type character against the printing surface for printing, and said for indicating the printing angular position of each said type character. an indicating device associated with a type character support disk and for reading said indicating device and providing a signal to said hammer device for controlling the printing of each character to obtain a uniform distribution of printed characters on the printed copy; and a reading device, said indicating device comprising a device provided on each said type character support arm and for indicating a force in accordance with the area of said type character associated, said force causing said hammer device to type each said type letter,
The pointing device comprises a pointing structure formed on each arm, each pointing structure having a predetermined dimension responsive to the reading device, the reading device sensing the pointing structure and sending a signal to the hammer device. A disc printing machine characterized by controlling the hammer force produced.